1. Field of the Invention
The present invention relates generally to the field of protocol converters. More specifically, the present invention relates to an emulator of an inertial navigation unit protocol converter on the P-3 aircraft.
2. Description of the Prior Art
The Department of Homeland Security utilizes airborne surveillance operations to monitor illegal activities which have an impact on national security. These activities include drug trafficking, illegal immigration, and terrorist activities.
Many ride-along sensor units often deployed with a surveillance P-3 aircraft require the implementation the National Marine Electronics Association 0183 (NMEA-0183) serial navigation data format. Future proposed components for geospatial video recording and reproduction also require the ability to utilize this format. There is currently an immediate need to provide aircraft navigation data in real time to produce a coherent video data stream for situational awareness during the transport of sensor video to the ground for analysis. The NMEA-0183 protocol provides a low bandwidth, commonly utilized format that end users can easily make use of for situational awareness.
An ARINC-429 to NMEA-0183 protocol converter was designed for use with the Litton LTN-92 Inertial Navigation System (INS), used on the P-3 aircraft, which is manufactured by Litton Industries, Incorporated. This protocol converter extracts commonly used parameters from the ARINC-429 protocol (such as time, date, position, ground speed and heading) and outputs a fixed set of NMEA-0183 sentences (such as RMB, RMC, GGA and GSA). The NMEA-0183 sentences provided by this protocol converter also provides pointing information that is used to indicate the location of an object relative to the P-3 aircraft. The protocol converter is described in co-pending U.S. patent application Ser. No. 11/499,983, which was filed Jul. 31, 2006.
However there is still a need for a device to bench test the protocol converter prior to the protocol converter deployment on a P-3 aircraft.